Spark Plug Service - Yamakoyo YK250 Owner's Manual

2. Wash the sediment cup and O-ring in nonflammable solvent, and dry them thoroughly.
3. Place the O-ring in the fuel valve, and install the sediment cup. Tighten the sediment
cup securely.
4. Move the fuel valve to the ON position, and check for leaks. Replace the O-ring if
there is any leakage.

SPARK PLUG SERVICE

Recommended spark plugs: F7RTC or other equivalents.
NOTICE
An incorrect spark plug can cause engine damage.
1. Disconnect the spark plug cap, and remove any dirt from around the spark plug area.
2. Remove the spark plug with a spark plug wrench.
SPARK PLUG WRENCH
.
3. Inspect the spark plug. Replace it if the electrodes are worn, or if the insulator is
cracked or chipped.
MAINTENANCE
SEDIMENT CAP
19
O-RING
0.028-0.031 in
(0.70-0.80 mm)